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GB/T 39701-2020 (GBT39701-2020)

GB/T 39701-2020_English: PDF (GBT 39701-2020, GBT39701-2020)
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BASIC DATA
Standard ID GB/T 39701-2020 (GB/T39701-2020)
Description (Translated English) Limit and test method of ammonium ion content in fly ash
Sector / Industry National Standard (Recommended)
Classification of Chinese Standard Q11
Classification of International Standard 91.100.10
Word Count Estimation 15,155
Date of Issue 2020-12-14
Date of Implementation 2021-11-01
Quoted Standard GB/T 6682; GB/T 8170; GB/T 12573
Drafting Organization China Building Materials Research Institute Co., Ltd.
Administrative Organization National Cement Standardization Technical Committee
Regulation (derived from) National Standard Announcement No. 28 of 2020
Proposing organization China Building Materials Federation
Issuing agency(ies) State Administration for Market Regulation, National Standardization Administration
Summary This standard specifies the limit and inspection method for the content of ions in fly ash. This standard applies to fly ash used as cement admixtures, mortar and concrete admixtures and other materials designated to adopt this standard.

Standards related to: GB/T 39701-2020

GB/T 39701-2020
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 91.100.10
Q 11
Limit and Test Method of Ammonium Ion Content in
Fly Ash
ISSUED ON: DECEMBER 14, 2020
IMPLEMENTED ON: NOVEMBER 01, 2021
Issued by: State Administration for Market Regulation;
Standardization Administration of PRC.
Table of Contents
Foreword ... 3
1 Scope ... 5
2 Normative References ... 5
3 Terms and Definitions ... 5
4 Technical Requirements ... 6
5 Preparation of Sample ... 6
6 Inspection Methods ... 6
7 Inspection Rules ... 6
Appendix A (Normative) Test Method for Ammonium Ion Content in Fly Ash -
Distillation Titration Method ... 8
Appendix B (Normative) Test Method for Ammonium Ion Content in Fly Ash -
Electrode Method ... 14
Appendix C (Normative) Test Method for Ammonium Ion Content in Fly Ash -
Nessler's Reagent Spectrophotometry... 18
Appendix D (Normative) Test Method for Ammonium Ion Content in Fly Ash -
Ion Chromatography ... 21
Limit and Test Method of Ammonium Ion Content in
Fly Ash
1 Scope
This Standard specifies the limit and test method of ammonium ion content in fly ash.
This Standard is applicable to fly ash that is used as cement admixtures, mortar and
concrete admixtures and other materials designated to adopt this Standard.
2 Normative References
The following documents are essential to the application of this document. For the
dated documents, only the versions with the dates indicated are applicable to this
document; for the undated documents, only the latest version (including all the
amendments) is applicable to this document.
GB/T 6682 Water for Analytical Laboratory Use - Specification and Test Methods
GB/T 8170 Rules of Rounding off for Numerical Values & Expression and
Judgement of Limiting Values
GB/T 12573 Sampling Method for Cement
3 Terms and Definitions
For the purposes of this Document, the following terms and definitions apply.
3.1 Ammonium ion in fly ash
Ammonium ions in the form of NH4+ attached to the surface of fly ash.
3.2 Series standard specifications for determining ammonium content of fly ash
Standard samples with different concentrations of ammonium ion content.
NOTE: It is used for comparative analysis to reduce the test error of ammonium ion content in
fly ash.
Appendix A
(Normative)
Test Method for Ammonium Ion Content in Fly Ash -Distillation
Titration Method
A.1 Principle
Mix the fly ash with water; adjust the pH to alkaline; perform distillation; absorb the
distilled NH3 by a dilute sulfuric acid solution; and transfer the ammonium ions in the
fly ash to the distillate. Take methyl red-methylene blue mixed indicator as indicator;
titrate the excessive sulfuric acid by sodium hydroxide standard titration solution; and
calculate the ammonium ion content in fly ash based on the NH4+ content in the
distillate.
A.2 Basic requirements of the test
A.2.1 Test requirements
The number of times for each test is specified as twice; and the difference between the
two test results shall be within the listed tolerance (see Table A.1), and the average of
the two test results is used to indicate the test result.
The blank test specified in this Standard can be carried out every 3 months when the
quality of distilled water remains unchanged.
It is recommended to use series standard specifications for determining ammonium
content of fly ash to reduce test errors.
In all titration processes, the needle-tube weighing method can be used instead of the
burette method of measuring the solution.
A.2.2 Expression of mass, volume and result
The mass is expressed in "grams (g)" and is accurate to 0.001g. The volume of the
burette is expressed in "milliliters (mL)", and the reading is accurate to 0.01mL. Refer
to the burette for the indication of the needle tube.
The ratio of concentration and volume of the standard titration solution retain three
significant figures. Unless otherwise stated, all analysis results are based on mass
fraction. The unit of ammonium ion content in fly ash is mg/kg, and it is retained to one
digit after the decimal point.
The rounding-off of the value is carried out according to GB/T 8170.
A.2.3 Blank test
Do not add fly ash, use the same amount of reagent, and perform the test in
accordance with the same measurement procedures.
A.2.4 General rules of reagents
Unless otherwise specified, the used reagents shall be no lower than the analytical
reagent, and the guaranteed reagent is preferred. The reagent used for calibration
shall be the reference reagent. The used water shall be no lower than the requirements
for Class-III water specified in GB/T 6682; and distilled water is generally used.
The density of commercially available concentrated liquid reagents listed in this
Standard refers to the density (ρ) at 20°C, and the unit is grams per cubic centimetre
(g/cm3).
In chemical analysis, any acid whose concentration is not marked refers to a
commercially available concentrated acid.
Unless otherwise stated, the validity period of the standard titration solution is 3 months.
If it exceeds 3 months, re-calibrate it.
A.3 Reagents and materials
A.3.1 Sulfuric acid (H2SO4)
1.84g/cm3, the mass fraction is 95%~98%.
A.3.2 Sodium hydroxide (NaOH)
Chemically pure.
A.3.3 Potassium hydrogen phthalate (C8H5KO4)
Reference reagent.
A.3.4 Ethanol (C2H5OH)
The volume fraction of ethanol is 95%.
A.3.5 Phenolphthalein indicator solution (10g/L)
Dissolve 1g of phenolphthalein in 100 mL of ethanol (A.3.4).
A.3.6 Sulfuric acid solution c(1/2H2SO4) = 0.1mol/L
Pipette 3mL of sulfuric acid; slowly pour into 1000mL of water; cool and shake well.
A.3.7 Sodium hydroxide standard titration solution c(NaOH)=0.1mol/L
A.4.1.1 Analytical balance: the division value is no more than 0.0001g.
A.4.1.2 Electronic balance: the division value is no more than 0.01g.
A.4.2 Glass volumetric utensils
A.4.2.1 500mL distillation flask.
A.4.2.2 50mL alkali burette.
A.4.2.3 250mL, 300mL beaker.
A.4.2.4 20mL pipette.
NOTE: It is recommended to use a pipette gun.
A.4.2.5 1000mL volumetric flask.
A.4.2.6 250mL graduated cylinder.
A.4.3 1000 W electric jacket
The capacity is 500mL.
A.4.4 Medical syringe
The capacity is no less than 30mL.
A.5 Test procedures
A.5.1 Preparation of distillate
Weigh 10g of fly ash sample (m2), accurate to 0.01g; and put it into a 250mL beaker.
In another graduated cylinder (A.4.2.6), pipette about 210mL of distilled water; mix the
distilled water and fly ash evenly and transfer it into a 500mL distillation flask (A.4.2.1).
In order to transfer all the fly ash into the distillation flask, the beaker shall be rinsed
twice.
Add about 0.2g of sodium hydroxide (A.3.2) in the distillation flask; quickly connect the
distillation device and ensure that it is sealed to prevent ammonia from escaping; and
wait for distillation.
Pipette 20.00mL of sulfuric acid solution (A.3.6) in a 250mL beaker; add 3 ~ 4 drops of
methyl red-methylene blue mixed indicator solution (A.3.8). Insert the glass tube at the
outlet of the distillation flask into the sulfuric acid solution at the bottom of the beaker.
Heating distillation, when the volume of distillate in the beaker reaches 200mL, stop
heating; remove the distillation flask; rinse the condenser by water; and collect the
washing liquid in the beaker.
Appendix B
(Normative)
Test Method for Ammonium Ion Content in Fly Ash - Electrode
Method
B.1 Principle
Mix the fly ash with water; transfer the ammonium ions in the fly ash to the filtrate; and
filter the mixture by filter paper. Then by adding a certain amount of ionic strength
adjuster to the filtrate to make the value of pH >12 of the test solution; the NH4+ in the
filtrate is converted into NH3; and the content of NH3 in the filtrate is analyzed and
determined by a high-performance ammonia gas sensing electrode, and calculate the
ammonium ion content in the fly ash.
B.2 Basic requirements of the test
The same as A.2.
B.3 Reagents and materials
B.3.1 Ammonium chloride
Dry ammonium chloride (NH4Cl, guarantee reagent) at 110°C for 2h; cool to room
temperature in a desiccator; and store in a sealed and dark place.
B.3.2 Ammonia stock solution (1mg/mL, NH3)
Accurately weigh 0.3142g of ammonium chloride dried at 105°C for 1h. Dissolve by a
small amount of water; transfer to a 100mL volumetric flask; dilute to the mark with
water; shake well; 1mL of this solution contains 1.00mg of ammonia.
B.3.3 Preparation of ammonia standard solution
Before the start of the test, the ammonia stock solution (B.3.2) is diluted step by step
into an ammonia standard solution with a concentration difference of 10 times
according to the following requirements.
a) Ammonia standard solution 1 (0.1 mg/mL, NH3): Before the test, use a pipette to
accurately pipette 10 mL of ammonia stock solution (B.3.2) in a 100 mL
volumetric flask; dilute to the mark with water; and shake well.
b) Ammonia standard solution 2 (0.01mg/mL, NH3): Before the test, use a pipette to
accurately pipette 10mL of ammonia standard solution 1 in a 100mL volumetric
flask; dilute to the mark with water; and shake well.
Appendix C
(Normative)
Test Method for Ammonium Ion Content in Fly Ash - Nessler's
Reagent Spectrophotometry
C.1 Principle
Mix the fly ash with water; adjust the pH value to alkaline for distillation; then absorb
the distilled NH3 by the dilute sulfuric acid solution; and transfer the ammonium ions in
the fly ash to the distillate. The ammonia nitrogen in the form of ammonium ion (NH4+)
reacts with the alkaline solution of mercury iodide and potassium iodide to form a
reddish-brown complex whose absorbance is proportional to the content of ammonia
nitrogen. The absorbance is measured at a wavelength of 420nm. Use the content of
ammonia nitrogen in the distillate to calculate the content of ammonium ions in fly ash.
C.2 Basic requirements of the test
The same as A.2.
C.3 Reagents and materials
C.3.1 Potassium sodium tartrate
Weigh 50.0g of potassium sodium tartrate and dissolve it in 100mL of water; heat it to
boil and drive off ammonia; dilute to 100 mL after cooling; and prepare it immediately
before use.
C.3.2 Nessler's reagent [mercury iodide-potassium iodide-sodium hydroxide
(HgI2-KI-NaOH) solution]
Weigh 16.0g of sodium hydroxide; dissolve in 50mL of water; and cool to room
temperature.
Weigh 7.0g of potassium iodide and 10.0g of mercury iodide; dissolve in water; then
slowly add this solution to the above 50mL of sodium hydroxide solution as stirring;
and dilute with water to 100mL. Store in a polyethylene bottle; cover tightly with a
rubber stopper or polyethylene cap; and store in the dark. The validity period is 1 year.
C.3.3 Sodium hydroxide solution (200g/L)
Weigh 20g of sodium hydroxide to dissolve in water; add water to dilute to 100mL.
C.3.4 Ammonia nitrogen standard solution
Appendix D
(Normative)
Test Method for Ammonium Ion Content in Fly Ash - Ion
Chromatography
D.1 Principle
Mix the fly ash with water; adjust the pH value to alkaline for distillation. Absorb the
distilled NH3 by the dilute sulfuric acid solution; and the ammonium ions in the fly ash
are transferred to the distillate, which is quantified by ion chromatography. The cation
analysis column is used for separation; the retention time of ammonium ions is
qualitative; the peak area or peak height is quantitative. The concentration of
ammonium ions (NH4+) in the absorption solution is determined, and then calculate the
content of ammonium ions in fly ash.
D.2 Basic requirements of the test
The same as A.2.
D.3 Ammonium standard solution
D.3.1 Ammonium standard stock solution (1000μg/mL)
Certified standard substance/standard sample, ammonium standard solution:
containing ammonium (NH4+) 1000μg/mL.
D.3.2 Preparation of ammonium standard solution (100μg/mL)
Pipette 25.00mL of ammonium standard stock solution (1000μg/mL) in a 250mL
volumetric flask; dilute to the mark with water; and shake well.
D.3.3 Drawing of ammonium standard working curve
Prepare the ammonium standard working solution according to actual needs; adopt
the stepwise dilution method; and use water as the blank solution at the same time.
The ammonium ion concentrations in the standard working solution are usually
0.00μg/mL, 0.10μg/mL, 0.50μg/mL, 1.00μg/mL, 5.00μg/mL. This solution is prepared
for current use.
Turn on the power according to the requirements of the ion chromatographic instruction
manual; and debug the instrument in the best working condition. Install the cation
chromatographic column and mobile phase, and when the system balances to a stable
baseline, inject a series of standard solutions into the ion chromatogram to obtain a
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